I Love GURPS

Side note: I love GURPS. I am absolutely baffled by how much someone can do with it. It really comes down to the simplicity of the system. A normal distribution standardized dice roll for all skills and checks is a very attractive thing. Furthermore, just about any setting or character can be modelled. Unlike Pathfinder or Dungeons & Dragons, the creation of a character is not limited by what sort of class or role you want to play. Instead, you formulate the character and build it within the system.